Simplify the following expression: $r = \dfrac{2p + 9}{4p} \div 10$
Explanation: Dividing by a number is the same as multiplying by its inverse. $r = \dfrac{2p + 9}{4p} \times \dfrac{1}{10}$ When multiplying fractions, we multiply the numerators and the denominators. $r = \dfrac{(2p + 9) \times 1} {(4p) \times 10}$ $r = \dfrac{2p + 9}{40p}$